I have had my iPhone4s for about a year. This week I noticed that I can barely keep the battery charged! My usage is mainly looking at emails, answering a few messages and listening to music/audiobooks. I don't do a lot of video/YouTube/games. In fact none at all lately.

Does anyone know what Apple considers enough battery loss to make a replacement?

The iPhone charged all night and battery is at 93%. Unplugged, charge drops quickly. When in the car, I use the USB charger. I noticed that the battery is not charging like it used to in the car.

I don't want to make the drive to the Genius Bar only to be told that I have to wait for the battery to be dead before a replacement will be made.